Nail pick

ABSTRACT

A nail pick for cleaning a nailbed comprises an elongated body that includes a handle at a proximal end and having a width as well as a cutting head at a distal end. The cutting head&#39;s width is less than the width of the handle. The cutting head includes a superior surface; an interior surface, opposite the superior surface, and first and second lateral side surfaces extending from the handle to the distal end. The first and second lateral side surfaces are concave-shaped and disposed between the superior surface and the interior surface. A first junction of the superior surface with the first lateral side surface defines a first cutting edge and a second junction of the superior surface with the second lateral side surface defines a second cutting edge.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 14/663,601, filed on Mar. 20, 2015, which claims priority to U.S. Provisional Application No. 61/971,619, filed on Mar. 28, 2014, the contents of which are hereby incorporated by reference in their entirety.

BACKGROUND

This invention relates to nail picks or other devices for cleaning (e.g., removing debris) from the nail beds of fingernails.

Hand hygiene is an important part of individual, family and community health. Many bacterial, viral, fungal, yeast and protozoal infections are transmitted by microbes that pass to and from the hands. Safe hands are essential in healthcare and in food processing and preparation. Safe hands are also needed in public facilities and the home.

As much as 95% of microbes on the hands are found beneath the fingernails; therefore cleaning under the fingernails is essential for effective hand hygiene. The bacteria, viruses, fungi and protozoans are concentrated in the deepest one millimeter of the nail bed. This area is generally warm and moist with an accumulation of oil, dirt and proteinaceous debris making that area a perfect incubator for microorganisms.

It is desirable to clean the fingernail bed to remove the microbes or kill them in place. Current approaches for effectively clean fingernail beds generally fail to adequately reduce the number of microbes.

Applying antimicrobial chemicals to the fingernail bed is not always effective. Such antimicrobial chemicals must reach sufficient concentration for a sufficient time to be effective. The tight dimensions of the nail bed and the impaction of debris in the depth of the nail bed keep the chemicals from effectively reaching their targets. Furthermore, the microscopic irregularities of the keratin layers of the undersurface of the fingernail provide shelter for the microbes that easily attach to the irregular surfaces within the nooks and crannies of the nail bed.

Water can dilute the number of microbes and, if presented at sufficient volume and velocity, dislodge them from their attachments to skin surfaces and the nail beds.

Hand brushes and nail picks have long been used to remove dirt, grease and microbes from skin surfaces of the hands and forearms and from beneath fingernails. They may improve the appearance of the fingernails by reducing gross contamination, but actually have limited effectiveness in sufficiently reducing the number of microorganisms. Even when combined with antimicrobial chemicals, including alcohol, brushes and nail picks leave 20-30% of the microbes present at the start of the cleaning effort. They have now been labeled ineffective and unnecessary for surgical hand preparation by most hospital and operating room protocols.

Any effort to degerm the hands must avoid injuring any skin surface. Healthy skin produces a natural boundary against microbes. If injured by chemicals, forceful or prolonged brushing, or the aggressive use of sharp instruments such as nail picks, the cleaning effort will be compromised. Unsafe hands will result.

One reason that present nail picks have fallen into disfavor is their design. Most disposable nail picks included with disposable brushes for surgical hand preparation are molded from plastic. None present a sharp surface to the underside of the fingernail sufficient to remove most of the debris and reshape or sculpt the rough, irregular keratin that forms the roof of the nail bed.

Studies have reported the number and types of bacteria and fungi that reside in nail beds of healthy subjects. While one individual tends to have consistent numbers in each of the ten nail beds, the numbers vary widely among the ten fingers and vary widely among different people. Some are easily reduced with traditional cleaning methods and others are highly resistant to any present effort to decrease their number. Not all factors that account for different numbers of resident flora are understood. Not all factors that account for resistance to cleaning are understood. It is likely that the tightness of the deep nail bed and the density, moisture content and configuration of the collagen within the keratin structure are important factors.

SUMMARY

In a general aspect of the invention, a nail pick for cleaning a nailbed includes an elongated body having a proximal end extending to a distal end. The elongated body has a longitudinal axis and includes a handle at the proximal end, the handle having a width extending transverse to the longitudinal axis. The elongated body also has a cutting head at the distal end. The cutting head has a second width that is less than the first width of the handle and includes a superior surface extending from the handle to the distal end; an interior surface, opposite the superior surface, extending from the handle to the distal end; a first lateral side surface extending from the handle to the distal end, the first lateral side surface being concave-shaped and disposed between the superior surface and the interior surface; and a second lateral side surface extending from the handle to the distal end, the second lateral side surface being concave-shaped and disposed between the superior surface and the interior surface. A first junction of the superior surface with the first lateral side surface defines a first cutting edge and a second junction of the superior surface with the second lateral side surface defines a second cutting edge.

Embodiments of the invention may include one or more of the following features. At least one of the first lateral side surface and the second lateral side surface is hollow-ground. The superior surface is convex in a direction transverse to the longitudinal axis. A plane defined by the superior surface lies at an angle substantially 30° from the longitudinal axis. This angle facilitates the precise positioning and, if necessary, forceful movement of the cutting edge when the nail pick is grasped using the crease of the palmar surface of the distal interphalangeal joint of the first finger and the palmar surface of the thumb in addition to other more proximal palmar surfaces of the remaining fingers. This ergonomically comfortable position uses three opposing surfaces to stabilize and precisely move the pick. Moreover, the 30 degree angle allows as second grasping position using the palmar surface of the thumb and the palmar surface of the distal phalanx of the first finger pinching grip just proximal to the cutting head of the pick. This may allow even greater fingertip control in applying the working surfaces of the pick to the nail and nail bed

The superior surface is raised from an associated surface of the handle. The inferior surface defines a non-cutting region of the cutting head. A curvature of radius of the inferior surface along the longitudinal axis is in a range between 3 mm and 5 mm.

Among other advantages, a nail pick is provided that has a geometry that helps to optimize both the effectiveness and ease of use for cleaning the underside of a fingernail bed.

Other features and advantages of the invention are apparent from the following description, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates the use of a nail pick for removing debris from beneath a user's fingernails.

FIG. 2A is a side view of the nail pick of FIG. 1.

FIG. 2B is a top view of the nail pick of FIG. 1.

FIG. 2C is an opposite side view of the nail pick of FIG. 1.

FIG. 3 is a perspective view of the cutting head of the nail pick shown in FIG. 1.

FIG. 4 is bottom view of the cutting head of the nail pick shown in FIG. 1.

FIG. 5 is another perspective view of the cutting head of the nail pick shown in FIG. 1.

DESCRIPTION

Referring to FIG. 1, a hollow-ground nail pick 10 is shown in use for cleaning a fingernail bed. For example, nail pick 10 can be used to remove debris (e.g., dirt, grease, proteinaceous debris, keratin debris and microbes) from beneath a user's fingernail 12. The nail pick 10 is made of a relatively rigid material such as stainless steel, aluminum or hard plastic. At a proximal end 11 of the nail pick 10 is a handle 14 sized and shaped to fit easily and comfortably into the hand 18 of the user. At its distal end, nail pick 10 also includes a cutting head 20 that, as will be described in greater detail below, has a geometry sized, shaped and optimized to effectively clean the underside of the fingernail nail beds and shape or sculpt the keratin surface of the nail.

Referring to FIGS. 2A, 2B and 2C, nail pick 10 has an overall length, here approximately 100 mm, suitable for comfortably fitting into the hand of a user. Handle 14 constitutes approximately 90% of the overall length of nail pick 10 with the cutting head 20 constituting approximately the remaining 10% of the overall length. In this embodiment, handle 14 and cutting head 20 have lengths of about 90 mm and 10 mm, respectively.

Handle 14 has a thickness of about 2 mm and narrows to cutting head 20, which has a thickness in a range between 1.33 to 1.53 mm. Cutting head 20 sits at an angle D, preferably at about a 30° angle to a longitudinal axis 21 of handle 14. Cutting head 20 includes a soft, non-cutting region 24, which facilitates accessing the fingernail bed without unnecessarily touching the ends of the finger being cleaned. Cutting head 20 also includes a raised section 26, which slopes into handle 14 at a beveled feature 28 to fit comfortably in the user's working hand 18. Beveled feature 28 allows the user to grasp the very distal portion of the pick 10 while keeping the raised section of the cutting head 20 unobstructed and the fingers holding the nail pick 10 away from the hollow-ground cutting edge (discussed in greater detail below). This is particularly helpful when using the pick 10 to work in a plane away from the middle of the nail bed, as in cleaning toward the little finger and away from the thumb or when grasping the tool with the pinching grip.

Referring to FIGS. 3 and 4, cutting head 20 includes a superior surface 30 and an inferior surface 32, opposite the superior surface 30, and both of which extend from the distal end of handle 14 to the distal end of nail pick 10. The superior surface, which is configured to contact the undersurface of the fingernail is approximately 10 mm in length and is slightly convex horizontally to allow close application and shaving of the undersurface of the nail in both directions. This allows the cutting head 20 to be precisely controlled to remove debris, shave off a layer of keratin and avoid impaling the undersurface of the nail. Cutting head 20 also includes lateral side surfaces 34, 36 that both extend from handle 14 to the distal end of nail pick 10. Lateral side surfaces 34, 36 are concave-shaped and are both disposed between superior surface 30 and interior surface 32. Cutting head 20 includes cutting edges 38, 40 which are defined by the junction or intersection of each of lateral side surfaces 34, 36 and superior surface 30.

Referring in particular to FIG. 3, cutting edges 38 and 40 are formed along the curved top of cutting head 20. As stated earlier, lateral side surfaces 34, 36 define cutting edges 38, 40 and are concave-shaped. More particularly, the concave-shaped surfaces of lateral sides 34, 36 provide hollow-ground cutting surfaces on each side of cutting head 20. The feature is symmetric about the longitudinal axis 21 of handle 14 of nail pick 10 and the radius of curvature of is in a range of 3 mm to 5 mm to aide in the arched scraping motion that occurs when moving the tool along the underside of the fingernail bed.

Cutting edges 38, 40 dislodge dirt, grease, proteinaceous debris, keratin debris and microbes that may have accumulated under the user's fingernail as well as carve off fine layers of keratin. A hollow-ground cutting edge and the convexity of the presenting surface allow the nail pick 10 to act as a knife and a chisel in displacing loose aterial and in reshaping the kerain surface with a blade that naturally returns to the surface with each stroke, decreasing the likelihood of impaling the edge in the keratin matrix and adding to the irregularity of the nail's undersurface rather than reducing it. This produces a smooth surface on the undersurface of the fingernail that will reduce colonization by microbes and more readily allow access of water and antimicrobial chemicals. The working arching motion is a natural result of the pivot point of the user's working hand, which occurs at the wrist when the nail pick 10 is grasped as shown in FIG. 1.

Referring to FIG. 5, the distal 5 mm of superior surface 30 has a curvature with a radius between 9 mm and 14 mm. Corners 44, 46 are gently rounded to protect any skin that may be contacted during the cleaning and sculpting movements of the tip. Superior surface 30 of the cutting head 20 is tapered from 1.4 mm at the distal-most tip of cutting head 20 to 2 mm at the proximal end of cutting head. This allows unrestricted movement of the cutting head so the natural shape of the fingertip will not compromise placement and movement of the tip deep in the nail bed. Superior surface 30 is slightly rounded at its distal end to allow placement and movement in the depth of the nail bed without injuring the delicate skin surface.

Referring again to the embodiment of the nail pick 10 shown in FIGS. 3 and 4, the shape of the sides of cutting head 20 are relatively sharp. This embodiment allows for improved capability in reaching deep corners of the nail bed. In other embodiments, superior surface 30, inferior surface 32 and lateral side surfaces 34, 36 may be shaped differently so as not be as sharp. Rather, cutting head 20 may be configured to have subtly but measurably rounded corners to avoid a scratch deep in the nail bed.

It is to be understood that the foregoing description is intended to illustrate and not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims. 

1-7. (canceled)
 8. A manufacture comprising a nail pick, said nail pick comprising a handle that forms a cutting head, wherein said cutting head comprises first and second cutting edges, a first lateral side surface, a second lateral side surface, a superior surface, and an inferior surface, wherein said handle that extends along a longitudinal axis between a proximal end and a distal end thereof, said handle comprising first, second, third, and fourth sides, said first and second sides being on parallel planes that extend along said longitudinal axis and a transverse axis perpendicular to said longitudinal axis, said third and fourth sides joining said first and second sides, said first and second sides defining a handle width along said transverse axis, and wherein said cutting head is formed from said distal end of said handle, wherein said third edge extends distally to form said inferior surface, and wherein said fourth edge extends distally to form said superior surface, wherein said cutting head has a cutting-head width along a direction parallel to said transverse axis, wherein said cutting-head width is equal to said handle width at a proximal end of said cutting head and decreases with increasing distance from said proximal end, wherein said cutting head narrows to a point that points in a direction in which said third edge faces, wherein said first and second lateral surfaces both extend between said inferior and superior surface, wherein said first cutting edge is defined by a junction between said superior surface and said first lateral surface, wherein said second cutting edge is defined by a junction between said superior surface and said second lateral surface, and wherein said first and second lateral surfaces are concave.
 9. The manufacture of claim 8, wherein said first lateral side surface is hollow-ground.
 10. The manufacture of claim 8, wherein said superior surface extends along a curve having a radius of curvature defined by an axis that is perpendicular to said longitudinal axis and said transverse axis and that extends through said cutting head.
 11. The manufacture of claim 8, wherein said superior surface extends along a line, wherein said line and said longitudinal axis define a thirty degree angle.
 12. The manufacture of claim 8, wherein said inferior surface defines a non-cutting region of said cutting head.
 13. The manufacture of claim 8, wherein said third edge has a raised step, and wherein said superior surface begins distal to said raised step.
 14. The manufacture of claim 8, wherein said inferior surface extends along a curve, wherein said curve has a radius of curvature, and wherein said radius of curvature is between three millimeters and five millimeters. 